1. Field of the Invention
This invention relates to adjustable furniture, for example chairs, beds or the like in which the position of one part of the furniture can be moved relative to another. The adjustment may be powered using electrical motors or the like or manual.
2. Description of the Related Art
Adjustable chairs are known in which the angle of the backrest can be changed in order to provide a recline position and/or in which a moveable footrest can be moved forwards and outward. Recliner chairs of this type are available in which the adjustment is achieved manually or by one or more electric motors. Some motorised chairs have the ability to incline the seat of the chair to assist the user out of the chair from a seated position to a standing position. Adjustable beds are also known in which a head and upper back supporting part of the bed can be moved to adjust the inclination of that part relative to other parts of the bed. So called ‘zero-wall’ recliner chairs have been developed which enable the recliner chair to be positioned with the backrest near the wall of a room or other item of furniture but also allow the backrest to be reclined without interfering with the wall. This can be achieved by the backrest movement being coordinated with movement of the seat and the surrounding structure of the chair which the backrest is pivotally connected to.
Typically the moveable parts of such items of furniture are supported upon relatively complex support arrangements, usually including a series of metal linkages, pins and bushes, with the linkages being moveable to allow the moveable part or parts of the furniture to travel through their respective range of movement. Such support arrangements are often mechanically complex, heavy and costly making transportation, handling and use awkward. These considerations place severe restrictions on furniture design. For example, an operating mechanism for a typical recliner chair with footrest may weigh in the region of 16 Kg or so. The complex series of linkages and connections in known support arrangements often results in manufacturing variations, due to tolerances etc, which affects the stiffness or resistance to movement of the moving parts. This is a particular disadvantage in the case of manually operated furniture where identical items of furniture may require different degrees of effort to be applied by the user to adjust the furniture.
There is a requirement, therefore, for an improved support arrangement for adjustable items of furniture, in particular a support arrangement which is mechanically less complex, less heavy and less costly than hitherto known arrangements.